People love to play musical instruments either for fun or to master an art. With improving technologies, several musical instrument-based applications available in smartphones or tablets help users improve their musical skills by, e.g., supporting practice with a metronome sound to mark time at a selected rate, recording/playing supporting music/lyrics in the background, etc. As with music, fitness and sports-related activities are a large and lucrative industry, and many users engaging in such activities desire their phones to be converted into smart sport/fitness companion.